Having already examined whether people should be allowed to hold and express unpopular beliefs, Mill looks at the question of whether people should be allowed to act on their opinions without facing legal punishment or social stigma. Mill observes that actions should not be as free as opinions, and reasserts that both must be limited when they would cause harm to others and be "a nuisance to other people." However, many of the reasons for respecting different opinions also apply to respecting actions. Since humans are fallible, different "experiments of living" are valuable. The expression of individuality is essential for individual and social progress.

Individuality is essential to the cultivation of the self. A basic problem that Mill sees with society is that individual spontaneity is not respected as having any good in itself, and is not seen as essential to well-being. Rather, the majority thinks that its ways should be good enough for everybody. Mill argues that while people should be trained as children in the accumulated knowledge of human experience, they should also have the freedom as adults to interpret that experience as they see fit. He places great moral emphasis on the process of making choices, and not simply accepting customs without questions: only people who make choices are using all of their human faculties. Mill then links the desires and impulses reflected in individuality with the development of character: "One whose desires and impulses are not his own, has no character, no more than a steam engine has character."

Mill writes that in early stages of society, it is possible that there could be too much individuality. However, the danger now is rather the stifling of desires and impulses. He says that people become more valuable to themselves and also more able to be valuable to others when they develop their individuality. Mill then turns to the second part of his discussion, the ways in which people who exercise their liberty as individuals are valuable to others.

Individuality is valuable because people might learn something from the nonconformists. Dissenters may discover new goods, and keep alive existing goods. While genius is rare, it is also true that "Genius can only breathe free in an atmosphere of freedom." Unoriginal people tend to not see the value of originality, and tend to shun genius for mediocrity. Mill argues against this tendency, saying that all people should value what originality brings to the world. Furthermore, Mill argues that the modern age (the 19th century), in contrast to the Middle Ages, tends to diminish the individual and encourage mediocrity, linking this tendency with the democratization of culture and government. A conscious effort needs to be made to counteract this trend.

There is no one pattern for how to best live life. If a person is sufficiently developed, then his choices for how to live life are best precisely because they are his own. People require different atmospheres in order to develop and reach their potentials, and a healthy society must make it possible for people to follow more than one pattern.

Liberty and individuality are essential to individual and social progress. Seeing people's dissimilarities is key in learning about one's own weaknesses. Diversity also lets us see the potential of combining the positive traits of different people. Forced conformity, in contrast, keeps people from learning from each other. Mill writes that it is "despotism of custom" that prevents the improvement of England, and that it is Europe's relative diversity of lifestyles and paths that makes it more progressive than conformist China. However, Mill worries that Europe is progressing towards the Chinese ideal of "making all people alike," and will thus face stagnation.

In this chapter, Mill tries to show that individuality and nonconformity are valuable both on the level of the individual and on the level of society. Mill believes that society naturally prefers conformity, and that this preference is exacerbated by democratization and the control of society by the masses.

Mill's concern with the stifling of individuality extends to both legal and social realms. He believes that in the face of public pressure to conform and the institutionalized power of over-reaching laws, the individual is obstructed from an ability to make meaningful choices, and thus from personal development. More broadly, and extremely important to any argument resting on the concept of utility, conformity hurts society as well as the individual in the minority, since in conformity people lose out on potentially desirable ways of approaching life and stop learning from each other. Mill believes that social progress requires a dynamic give and take between conflicting ways of life.

Mill's views of social progress are intimately tied up with his views on individuality and conformity. Mill subscribes to the belief that there are better and worse ways to live life: barbarians and savages, Mill believes live more poorly than civilized man. But, with civilization comes a tendency toward conformity. And since Mille believes that it is through a free and dynamic development of one's self and the interaction with people with different ways of life that an individual perfects himself, and similarly, that it is through discussion and dissent that "truth" is kept alive in society, conformity leads to social stagnation. There may be such a thing as too much individuality, as a barbarian nation is structured (or unstructured). Conformity, however, the opposite of too much individuality, is similarly problematic, and leads only to a lack of vitality. Mill here outlines a relationship between the liberty of man and society that is dynamic, a constantly negotiated terrain; there is a delicate balance, the individual must always be free, but the specter of too much freedom, as embodied by the uncivilized world, does exist.

Mill does not give many examples in this chapter, and his discussion of liberty of action is quite general. Thus, it is important to think about what individual "liberty" Mill truly considers to be necessary for human and social development. If by liberty he merely means permitting eccentricity, then it is not clear that his position is very radical all. However, if Mill wishes to encourage people to act out against deeply engrained social norms, then one might wonder if society might simply lose cohesion and become polarized under his system. One might also wonder if there aren't some actions that are simply worthless for human development. The next two chapters provide some real examples of Mill's principles in action. When reflecting on these examples, think about whether they are consistent with Mill's arguments and predictions in this chapter.